Computer Simulation Of Ride Comfort On The Air Suspension Of Commercial Car

The air spring suspension takes on many virtues,for example,its stiffness isvariable,vibration frequency is low, it have greater reliability and when operation,the body height remains constant. Air suspension has widely used incoach ,because Ministry of Communications issued the standard of 《Typedividing and class rating for Commercial motor -vehicles of passengertransport》,in which the air suspension must be used in the higher-level coach andover higher-level coach.And now, more and more engineers and manufacturerspay attention to studying the performance of this kind of suspension.In this thesis, both a kinetic model and a mathematical model of 1/2 bus of 4DOFs are built, according to Yaxing-Benz Bus YBL6115H. Using the rationalfunction power spectrum the parameter, we establish the road surface the timedomain model which drove to the bus, and fit the air spring rigidity curve with thepartition linear interpolating function and least squares method. The softwareMATLAB and its toolbox SIMULINK are used to build the road surface rankedGrade B ,and simulate and analyze the bus's ride comfort. Then we obtain the 4DOFs' accelerations' PSD and RMS, here, 4 DOFs respectively are front shaft,rear shaft,floor boards above the front shaft and rear shaft. At the same time,according to the national criterion (GB/T 4970-1996)《,The Vehicle's Ride ComfortUnder Random Input》 ,we carry out road test on the vehicle ride comfort, andobtain corresponding accelerations' PSD and RMS. Then compare the test resultswith the simulation results, evaluate the feasibility of the model and the vehicle'sride comfort. At last, by changing the model's parameters, we put forward someadvice on improving ride comfort.Finally, we put forward some questions to solve in following days.